WHEAT FARMERS MAY SOON use biotechnology to take on "take-all," a fungus that attacks the roots of wheat plants, turning them black as it eats them alive. Take-all cuts wheat yields by an average of 15% in the Northwestern U.S., where moist soil conditions favor fungal growth.
The biotech battle against take-all began in 1988, when Agriculture Dept. researchers identified a natural antibiotic produced by soil-dwelling Pseudomonas fluorescens bacteria. The researchers isolated the genetic coding for the antibiotic in 1992. Since then, they have placed the genes in other strains of Pseudomonas that are better suited for particular wheat-growing conditions. They have also learned to mass-produce the bacteria and coat them onto the wheat seeds in batches as large as 1,000 pounds. "It is all coming together," says R. James Cook, research leader for the USDA's Root Disease & Biological Control Research Unit in Pullman, Wash.
The USDA is about to settle on choosing a commercial partner to aid in its quest for the needed Environmental Protection Agency approval. Cook expects commercialization of the process within three years.